If you are using the latest version of LimeWire, this is happening because LimeWire has detected a corruption in the file and is redownloading the parts that are corrupt. LimeWire will attempt to do this up to six times. If, after the sixth time, it still fails, then it will let you know the file is corrupt.

Perhaps we should make this more clear ... Do you have any suggestions on how to do that?

Thanks.